Holy Mackerel, Kingfish!

Q. Where did the mackerel in Holy Mackerel come from?

A. Often, when you see holy preceding another word, it’s a euphemism (Holy Smokes, Holy Cow, Holy Moley). For reasons of delicacy towards others or fear of offending God, the speaker will often substitute a less offensive word in the original phrase. Quite often, it will be a word beginning with the same letter or rhyming with the word that it replaces. So in this case, it’s likely that the original was Holy Mary or Holy Mother of God; Holy Mackerel is a softer, gentler way of expressing it.

A quick search on google reveals that it’s currently used as the name of an indie folk label, a rock band, a tackle shop, a seafood restaurant in Australia, a font family, and some cat treats. Because the fish had dark wavy bars on its back and a silvery belly, it gave rise to the term a mackerel sky, also known as a buttermilk sky.

But why mackerel instead of marble or milkmaid or mudpies? It may be related to the insulting or derisive term mackerel snapper. This was a reference to a Roman Catholic, and it recalls the former Catholic custom of abstaining from meat on Fridays, eating fish instead. The mackerel was an important food fish, widely distributed in the Atlantic Ocean. Snapper in the phrase refers to a biter, an eater, not to someone who cracks a fish’s backbone. In 1855, it also appeared in print as mackerel snatcher.

This answer was followed by a related question the very next week:

Q. “I had the bad habit of saying holy mackerel also. When we lived in France, I discovered that mackerel is some form of dirty word. I was so embarrassed; it did not cure me from saying it, but I did not say it in France! Why was it socially unacceptable?”

A. My Francophile son provided the answer. In French, maquereau means mackerel, but it also is used to designate a pimp. In folklore, the mackerel allegedly would lead fish to their spawning grounds, making it a procurer of sorts. I have seen speculation that Mack Daddy has maquereau as its origin.